This is a renewal application for years 28-32 of GM07171 which supports the Medical Scientist Training Program (MSTP) at Duke University. One of the first MSTP's, this Program has been continually funded by the National Institutes of General Medical Sciences, the first ten years as GM01678 (1966-1975) and the subsequent 26 years as GM07171 (1975-2001). The Program currently has an award of 36 funded positions and is requesting the same number of slots in this renewal. However, the Program has grown significantly since the previous application in 1996 when there were 42 students. Currently, there are 57 students and the Program will reach a new steady state of 70-84 students. This number represents 10 to 12% of the Medical School class. The additional funding is provided by the Medical and Graduate Schools, the Duke Medical Alumni Association, and the Duke Endowment. In addition, an $800,000 reserve fund has been created to cover unexpected financial needs by the Program. As of this writing, 14 of 16 applicants accepted by the Program have indicated their intention to matriculate here. The current Program student body is quite diverse with 17.6% underrepresented minority enrollment and a gender distribution that is 44% female. A large pool of applicants (200-300 per year) has allowed us to recruit an outstanding group of students. The structure of the Program is unchanged since the prior application. It consists of a basic science core year, a clinical core year, graduate school, and return to a final clinical year. The average program length is 7.2 years. Students may spend their graduate years in the traditional Medical School basic sciences, Chemistry, Zoology, and Biomedical Engineering. Greater flexibility is now available to our students who may also opt a new Biostatistics and Bioinformatics department, Economics, or Cognitive Neuroscience/Psychology.